Medical Gas Backfeed

Medical air is one of the most crucial medical gases serving an NFPA 99 Category 1 facility or space. It is typically responsible for keeping ventilators and blenders running and downtime of any length is simply not acceptable.

 

When work must be performed on the air compressor source, especially within the control panel, power may have to be disrupted to safely complete that job. One way that EMGS helps ensure that the medical air supply remains uninterrupted is to provide a back feed manifold setup located just downstream of the medical air dryers but upstream of the source valve (or at an auxiliary valve, if available, immediately downstream of the source valve).

The back feed manifold is a fairly simple setup while still allowing for change out of one cylinder at a time. The manifold can be extended to more cylinders if the facility flow is very high, or the duration of shutdown is long enough to require it.

Feel free to contact us if you have any questions about medical air or any other medical gas or vacuum temporary setups. We offer rental manifolds, rental medical vacuum systems and rental medical air systems to help with your next shutdown.

Do medical gas cylinders have to be protected from direct sunlight?

NOTE: All references taken from NFPA 99 – 2012 edition

We get this question from customers with medical gas manifolds installed outdoors sometimes. NFPA 99 addresses this question directly in chapter 11 where it talks about protecting gas cylinders stored outdoors:

Note: sub-paragraph (3)
11.6.5.4 Cylinders stored in the open shall be protected as
follows:
(1) Against extremes of weather and from the ground beneath
to prevent rusting
(2) During winter, against accumulations of ice or snow
(3) During summer, screened against continuous exposure
to direct rays of the sun in those localities where extreme
temperatures prevail

If you have a gas manifold installed outdoors then you need to ask yourself this question: am I in a location where extreme temperatures prevail?  If the answer is yes then you should take steps to protect those gas cylinders from direct sunlight, if the answer is no then maybe you’re fine.  Keep in mind that the AHJ (Authority Having Jurisdiction) will ultimately determine if you’re in a location where extreme temperatures prevail.  It may be worth asking your AHJ what they think if you have the relationship with them where that is feasible.

Sub-paragraph (1) & (2) from this reference should not be ignored either.  Rust on cylinders is a common problem so ensure that your concrete pad is well drained and free of dirt & mud.  Ice & snow buildup can be a major issue in the northern states, being diligent and keeping the pad clear so that it can be navigated by personnel is important after a big snowstorm.

If you have any further questions regarding outdoor cylinder storage or any other aspect of NFPA 99 please give us a call at 1-888-256-EMGS (3647)

Rebuilding Amico & Beacon Medaes Outlets (Series B style, Diamond style quick connect)

When you have a hospital of any age it is likely that you probably have outlets manufactured by more than one company. When this happens you may get outlet repair parts mixed up especially in the case of Amico and Beacon (Series B) style outlets. If you’ve ever rebuilt the latch valve of one of these outlets and noticed that you fixed the leak but created a flow problem (low or no flow) the reason is because of the dust cap used by Amico and Beacon Medaes.

At first glance they appear to be identical, but upon further inspection you will notice subtle differences in each one. Amico has two different styles that come in their standard repair kit, a white cap and a gray cap. The gray cap can be put aside because we are talking specifically about Ohmeda/Medaes Diamond style quick connect outlets. The gray dust cap is specifically for Chemetron (Allied Healthcare) style vacuum inlets.

In the picture below you will note a couple of key differences. The front of the Beacon Medaes dust cap has three lines that meet in the middle to form a triangle. The Amico dust cap is flat with no texture. If you look at the back you will notice another key difference and this is what can cause flow issues. The Amico has a raised portion on the inside front of the dust cap, but the raised portion is solid. The Beacon Medaes dust cap also has a raised portion but it is hollow and has a hole in the middle, this allows the brass poppet to seat slight further within the barrel than on the Amico latch valve. That is why mixing the dust caps can cause no flow issues when Amico dust caps are used on Beacon Medaes outlets.

The moral of the story is be sure to keep your outlet parts segregated and use the appropriate manufacturer repair parts for each individual outlet or inlet.

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NFPA 99 Zone Valve Labeling – New Construction vs. Existing Facilities

Zone Valve Box

There are two types of zone valve references that address labeling in NFPA 99 (2012 edition). One is for new construction projects which is located here:

  • 5.1.4.8.8 Zone valves shall be labeled in accordance with 5.1.11.2.
  • 5.1.11.2 Shutoff Valves.
  • 5.1.11.2.1 Shutoff valves shall be identified with the following:
    (1) Name or chemical symbol for the specific medical gas or
    vacuum system
    (2) Room or areas served
    (3) Caution to not close or open the valve except in emergency
  • 5.1.11.2.2 Where positive pressure gas piping systems operate at
    pressures other than the standard gauge pressure of 345 kPa to
    380 kPa (50 psi to 55 psi) or a gauge pressure of 1100 kPa to
    1275 kPa (160 psi to 185 psi) for nitrogen or instrument air, the
    valve identification shall also include the nonstandard operating
    pressure.

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The other reference is for existing facilities (which apply during projects such as the annual testing we perform), and that reference is located here:

(NOTE: The * next to Valves indicates that there is additional information available in the annex material. The annex isn’t “technically” enforceable however many inspectors do not seem to care because they enforce items out of the annex all of the time. Zone valves aren’t directly mentioned in this section of chapter 5, just in the annex of chapter 5.)

  • 5.1.14.2.3.1 General. The elements in 5.1.14.2.2.2 through
    5.1.15 shall be inspected or tested as part of the maintenance
    program as follows:
    (8)*Valves — labeling

The * refers to:

  • A.5.1.14.2.3.1(8) Additional inspections for zone valves include
    the following:
    (1) Locations (relationship to terminals controlled)
    (2) Leaks
    (3) Labeling
    (4) Housekeeping around alarm